Longest Palindrome by Concatenating Two Letter Words.cpp

// Runtime: 823 ms (Top 29.55%) | Memory: 167.6 MB (Top 95.91%)
class Solution {
public:
    int longestPalindrome(vector<string>& words) {

       int count[26][26] = {};
       int ans =0;

            for(auto w : words){
                int a = w[0] - 'a';
                int b = w[1] - 'a';

                if(count[b][a]){
                    ans+= 4;
                    count[b][a]--; // decrement the count as we found mirror word
                }else
                    count[a][b]++; //increment the current word count if we not find any mirror word
            }

            for(int i=0;i<26;i++){
                if(count[i][i]){
                    ans+=2;
                    break;
                }
             }

    return ans;

    }
};